2 1/2" Bearing UCP213-40 Black Oxide Plated Insert + Pillow Block Cast Housing Mounted BearingUCP213 40 Black Oxide Plated Insert Pillow Block Bearingt 2 1 2" Inch Inner Diameter UCP213 40 Pillow Block Bearing, UCP213 40 is Set Screw Type High Center Height, Inner Diameter is 2 1 2" Inch. Black oxide has certain properties and characteristics that makes it ideal for certain applications. It is used to add corrosion resistance and for appearance. UCP213 40 Black Oxide Plated Insert Bearing + Pillow Block Pillow Block Mounted Bearing Bolt Size: